Import of unmolested less-290.

1 files changed, 117 insertions, 0 deletions

diff --git a/usr.bin/less/brac.c b/usr.bin/less/brac.c
new file mode 100644
index 00000000000..1d484b83bce
--- /dev/null
+++ b/usr.bin/less/brac.c
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 1984,1985,1989,1994,1995  Mark Nudelman
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice in the documentation and/or other materials provided with 
+ *    the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 
+ * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN 
+ * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+/*
+ * Routines to perform bracket matching functions.
+ */
+
+#include "less.h"
+#include "position.h"
+
+/*
+ * Try to match the n-th open bracket 
+ *  which appears in the top displayed line (forwdir),
+ * or the n-th close bracket 
+ *  which appears in the bottom displayed line (!forwdir).
+ * The characters which serve as "open bracket" and 
+ * "close bracket" are given.
+ */
+	public void
+match_brac(obrac, cbrac, forwdir, n)
+	register int obrac;
+	register int cbrac;
+	int forwdir;
+	int n;
+{
+	register int c;
+	register int nest;
+	POSITION pos;
+	int (*chget)();
+
+	extern int ch_forw_get(), ch_back_get();
+
+	/*
+	 * Seek to the line containing the open bracket.
+	 * This is either the top or bottom line on the screen,
+	 * depending on the type of bracket.
+	 */
+	pos = position((forwdir) ? TOP : BOTTOM);
+	if (pos == NULL_POSITION || ch_seek(pos))
+	{
+		if (forwdir)
+			error("Nothing in top line", NULL_PARG);
+		else
+			error("Nothing in bottom line", NULL_PARG);
+		return;
+	}
+
+	/*
+	 * Look thru the line to find the open bracket to match.
+	 */
+	do
+	{
+		if ((c = ch_forw_get()) == '\n' || c == EOI)
+		{
+			if (forwdir)
+				error("No bracket in top line", NULL_PARG);
+			else
+				error("No bracket in bottom line", NULL_PARG);
+			return;
+		}
+	} while (c != obrac || --n > 0);
+
+	/*
+	 * Position the file just "after" the open bracket
+	 * (in the direction in which we will be searching).
+	 * If searching forward, we are already after the bracket.
+	 * If searching backward, skip back over the open bracket.
+	 */
+	if (!forwdir)
+		(void) ch_back_get();
+
+	/*
+	 * Search the file for the matching bracket.
+	 */
+	chget = (forwdir) ? ch_forw_get : ch_back_get;
+	nest = 0;
+	while ((c = (*chget)()) != EOI)
+	{
+		if (c == obrac)
+			nest++;
+		else if (c == cbrac && --nest < 0)
+		{
+			/*
+			 * Found the matching bracket.
+			 * If searching backward, put it on the top line.
+			 * If searching forward, put it on the bottom line.
+			 */
+			jump_line_loc(ch_tell(), forwdir ? -1 : 1);
+			return;
+		}
+	}
+	error("No matching bracket", NULL_PARG);
+}